Aerospace laminates are widely used throughout the aerospace industry. They provide high strength and low weight structures that are responsible for increased efficiency, reduced costs, improved performance, and broadened applications within the aerospace field. Although aerospace laminates are widely utilized and are credited with a wide variety of benefits and savings when applied to aerospace structures, they often present undesirable characteristics when implemented by modern practices.
Aerospace laminates are traditionally fabricated through the application of a plurality of pre-impregnated plies, such as fabric plies, to a tool surface. Commonly these plies, also known as prepreg, are manually positioned and applied to the tool surface in order to insure the individual layers are applied in a wrinkle free manner. The process of manually positioning and applying these layers is commonly referred to as “hand lay-up”. The hand lay-up process can be labor intensive. Additionally, the manual nature of the process can result in variability of the resultant structure which is highly undesirable. Finally, hand lay-up processes are often impractical when applied to large-scale structures. Large scale structures can present ergonomic problems for lay-up technicians. All of these concerns developed from the hand lay-up process are known to negatively impact the labor costs of the resultant structure. Labor can account for more than half the cost of such composite structures.
A solution that eliminates the negative cost and efficiency associate with hand lay-up is to automate the process. Several existing processes are known wherein composite materials can be laid down by automated means. These include fiber tow placement, filament winding, and tape laying. Although these approaches provide limited functionality, they are often found to be undesirably limited in the width of material that they can apply. In addition, often these approaches are compatible only with unidirectional fiber and not woven fabric. Since fabric can have significant advantages over unidirectional composites in many applications, hand lay-up has remained common in spite of the known and existing automated composite fabrication processes in use today.
It would therefore be highly desirable to have an apparatus and method for automated fabric lay-up of aerospace composite laminate that took advantage of the benefits of woven fabric composites. It would further be highly desirable to develop an apparatus and method for automated fabric lay-up of aerospace composite laminate that eliminated the labor-intensive hand lay-up process that has often been necessitated by fabric use.